Chronic kidney disease indicates a disease in which there is chronic deterioration of renal function, and even if the same kidney disorder, is differentiated from acute nephritis and the like. Since the kidneys fulfill the role of removing by filtration waste products in blood, waste products buildup in the body when renal function deteriorates, leading to the showing of so-called uremic symptoms. Also, by the discharge of useful nutritional components and ions through urine by deterioration in the filtration function, leading to malnutrition and electrolyte loss, and the reduction in the kidneys of the produced amount of hematopoietic factor erythropoietin, renal anemia may result. As can be seen from the Japanese saying that that which is very important can be called “liver and kidneys” by lining up the first Japanese Kanji character of liver and kidneys, which are two organs for toxicant metabolism, the kidneys are a silent important organ.
The progression of renal function deterioration causes uremia, which causes symptoms such as nausea, grumpiness, fatigue, swelling, dizziness, hypertension, and breathing difficulty. When neglected, renal failure occurs and there is even death.
Regarding chronic kidney disease, although there are examples in which there is transition to chronic kidney disease by there being no recovery from acute renal failure caused by injury, shock or the like, it normally starts by renal function gradually deteriorating over a long period of time. Also, it is said that in many cases, chronic kidney disease involves kidney contraction, and once contracted, the kidneys will not recover.
In order to slow progression of the disease, primarily alimentotherapy and life control are performed, work is restricted in order to reduce stress, and proteins and salt are restricted in order to reduce strain on the kidneys. However, dietary restrictions over the long term place a large burden on patients.
Although drugs for directly treating chronic kidney disease are not known, the main drugs currently used from ameliorating chronic kidney disease are listed below.
1) Adrenocortical hormones, immunosuppressants
Used as symptomatic therapy for nephritis, nephrotic syndrome, and the like.
2) Antiplatelet drugs
Although used for the purpose of reducing the load on kidneys by improving blood flow, there is the risk that hemorrhaging will not stop.
3) Hypotensors (Ca antagonists, ACE inhibitors, ARB drugs, α-blockers)
Used for the purpose of reducing the load of kidneys by lowering blood pressure.
4) Calcium preparations, active vitamin D formulations
Used as a countermeasure for calcium deficiency at the time of renal function deterioration.
5) Iron preparations, erythropoietin
Used as a countermeasure for anemia at the time of renal function deterioration.
6) High uric acid therapeutic agents
Used as a countermeasure for high uric acid at the time of renal function deterioration.
7) Hyperlipidemia therapeutic agents
Reduces the load on kidneys by lowering serum cholesterol.
8) Diabetes therapeutic agents (sulfonyl-type, nateglinide-type, biguanide-type, insulin, and the like)
Used in the treatment of diabetes in diabetic renal disease.
All of these are for the purpose of delaying progression of the disease by symptomatic therapy or adjunctive therapy without directly improving renal function, and thus no fundamental pharmaceutical for chronic kidney disease presently exists.
Presently, fundamental treatment of renal function deterioration is limited to kidney transplantation or dialysis. However, kidney transplantations not only place a load on the patient, but there are also problems with the kidney donor. Also, dialysis heavily restricts the pattern of life since a patient is periodically restrained for a long period of time and treatment costs said to be 10,000,000 yen each year per patient are directly connected to the social problem of the national cost of medical care soaring.
Although urine tests measuring hematuria and the amount of proteins are adjunctively used for renal function, renal function is primarily determined using the serum creatinine value and the estimated glomerular filtration rate (eGFR) calculated by the following formula from the serum creatinine value and age.
Calculating formula estimating GFR (glomerular filtration rate)
Units: mL/min/1.73 m2 
Male: eGFR=194×Cr−1.094×age−0.287 
Female: eGFR=0.739×calculating formula for male eGFR
When the above-mentioned eGFR becomes less than 90, it is determined as kidney disease, when it becomes less than 60, subjective symptoms such as swelling appear, when it becomes less than 30, dialysis preparation is necessary, and when it becomes less than 15, the possibility of death by uremia increases if kidney transplantation or dialysis is not performed. When suffering from chronic kidney disease, there is normally no improvement in the eGFR value and there is only delay in progression of the disease by abstinence and symptomatic therapy. In Japan, one person in every eight people is a chronic kidney disease patient and there is said to be 13,300,000 patients. There are presently 260,000 patients receiving dialysis and this is increasing yearly by 10,000 people. The development of therapeutic drugs for chronic kidney disease has become a national problem for saving the beleaguered medical economy let alone saving patients.
Also, it is known that chronic nephropathy causes aneamia by reduction in the production of erythropoietin, which is a hematopoietic factor. Regarding the relationship between anemia and ALA, it has already been reported that ALA is effective in preventing anemia in piglets (for example, refer to Patent Document 1).